Generally, in a secondary battery represented by a lithium ion battery, charge-discharge characteristics deteriorate when a temperature decreases. For example, in a lithium ion battery, when it is charged under a low temperature, deposition of lithium (Li) occurs in a negative electrode, and deterioration in performance such as a reduction of a capacity of the battery occurs. Therefore, when the temperature of a battery is low, it is necessary to rapidly elevate the temperature of the battery.
Japanese Patent Laying-Open No. 11-329516 (Patent literature 1) discloses a temperature elevating apparatus of a battery. In this temperature elevating apparatus, a series circuit made up of an inductor, a capacitor and an AC source is disposed on each end of the battery to form a resonance circuit. Then, by generating AC voltage of the resonance frequency of the resonance circuit from the AC source, a temperature of the battery is elevated.
In this temperature elevating apparatus, electric power is consumed mostly by the internal resistance of the battery at the time of the resonance, and the temperature of the battery is elevated by self heat generation. Therefore, according to this temperature elevating apparatus, it is alleged that the temperature of the battery can be elevated efficiently with minimum consumption of the electric power (see Patent literature 1).